Resistance unit and method of making the same.



E. F. COLLINS. RESISTANCE UNIT AND METHOD OF MAKING THE SAME. APPLICATION HLED DEC.29. I916- Patented July 10, 1917. Fig. l. Fig. 2. Fig.7. egg 0 r 7 H EEG";

/a Inventor: j Edgar F. Collins,

His flttorneg UNITED PATENT OFFICE.

EDGAR E. COLLINS, 0E SCHENECTADY, NEW roan, ASSIGNOB 'ro GENERAL ELEcrnIc COMPANY, A conrom'rron or NEW YORK.

.. RESISTANCE UNIT AND METHOD o rAKmG THE smE.

Specification of Letters fatent. Patented uly 10, 1917.

Application filed December 29, 1916. Serial No. 139,454.

To all whom it may concern: 7

-Be it known that I, EDGAR F. COLLINS, a citizen of the United States, residing at Schenectady, in the county of Schenectady, State of New York, have invented certain new and useful Improvements in Resistance Units and Methods of Making the Same, of which the followin is a specification.

My invention re ates to a resistance unit and the method of making the same and has for its object the improvement in the manufacture of a device ofthis character.

One of the objects of my invention is the provision of a heater for air or othergases which is provided with a large radiating surface and which is formed to admit of a free circulation of the air to be heated there through in order that the air may be quickly brought to the desired temperature and may be maintained at a temperature Wh'lClI is, relatively, not far below that of the resistance element itself. It will be understood, however, that the use of my heater is not confined to those applications where such conditions arepresent but iscapable of general application.

Another object of my invention is the provision of a simple, compact and efiicient heater of the above character.

For a fuller understanding of my invention, reference may be had to the accompanying drawings, showing one embodiment thereof, in which Figure 1 is a plan view of a portion of the punched blank prior to the bending of the strips; Fig. 2 is a similar View but with the individual strips turned through an angle of 180 degrees and the strips arranged edgewise to the plane of the resistance element; Fig. 3 is a perspective view of the resistance element shown in Fig. 2; Fig. i is an end view thereof; Fig. is a plan view of a heating dev ce embodying my invention; Fig. 6 is an end v1ew of Fig. 5; Fig. 7 is a sectional View through one of the supports; and Fig. 8 is a diagrammatic view illustrating the circuit connectlons.

Referring now to the drawings, a blank A is first formed preferabl by stamping the same from sheet metal 0 suitable resistance material. The blank, which is an integral piece, comprises successive strips 10, connected together at alternate ends as at 11, and having suitable slots 12 between the successive strlps. The successive strips are provided with stiffening ribs 10 and formed at alternate ends with supporting extensions or ears 13, extending transversely of the strips, and also extending across the end of the next succeeding stri as clearly shown in Fig. 1. The extensions 13 are. provided with openings 14 for engaging the support, as will be more fully hereinafter described.

The strips are now successively bent at the lines 15 through an angle of 180 degrees, the successive strips being bent in opposite directions to bring the extensions 13 all on the same side of the resistance unit, as shown in Fig. 3, and to bring the strips into the form of a grid with the strips edgewise arranged to the plane of the resistance unit. The resistance elements are mounted on supports B comprising rods 16 on the ends of which are carried the brackets 17 formed with angular ends 18 which are in turn provided with slots 18 by which the brackets may be secured to any desired base support. Insulating washers 19 are threaded on the supporting rods 16 and are preferably provided on one face with bosses 20, and on the opposite face with corresponding recesses 21 for the reception of the boss on the adjacent washer. The washers are provided with openings 22 in which the rods 16 are received. The extensions or ears 13 of the resistance elements are received between the successive washers, the bosses 20 passing through the openings 14 on the extensions or ears 13. In the preferred form of my invention, two supporting rods with the associated parts are provided for each resistance element, the extensions 13 at one end of the resistance element engaging one support and those at the other end engaging the other support.

In order the better to economize space, I

preferably mount two resistance elements on each set of supports, one on either side thereof, as best shown in Figs. 6 and 7, and in this construction the extensions 13 at one end of a given element are carried on alternate washers, the corresponding extensions on the other side of the support being received on the remaining washers of the given support. The two elements are preferably connected in series. This may con-' veniently be done by connecting the last strip of one element to that of the other, by brazing or otherwise connecting a piece 23 to these two strips asshown in Fig. 5.

Suitable terminals 24 and 24: are pro- 119 vided for the respective elements. The heating elements together with the supporting washers therefor may conveniently be clamped in position by nuts 25.

One particularly useful application of mv invention is in the heating of enameling and similar ovens, where the flashing point of the gases evolved from the enamel is, relatively,not greatly in excess of the required enameling temperature. It is necessary, therefore, that the difference in temperature between the heating unit for such an with my invention may be used in any location where a heating unit of this character is desirable.

In accordance with the provisions of the patent statutes, I have described the principle of operation of my invention, together with the apparatus which I now consider to represent the best embodiment thereof; but I desire to have it understood-that the apparatus shown is only illustrative, and that the invention can be carried out by other means.

What I cla1m as new and desire to secure by Letters Patent of the United States, is

1. The method of making a resistance element which consists in forming an integral blank comprising successive strips or ribbons connected at alternate ends and provided with perforated ears and then bending the successive connecting portions in opposite directions and alining the perforations.

2. The method of making a resistance ele-' ment which consists in stamping from sheet metal an integral blank comprising succes sive parallel strips or ribbons connected at alternate ends and with ears formed beyond the connecting portions and extending transversely of the strips, and bending the supports.

successive connecting portions in opposite directions tobring the element into the form of a grid with the strips arranged edgewise to the plane of the element and the ears to one side of the resistance strips for engaging supports.

3. A resistance element comprisingan integral conductor formed of successive metal strips or ribbons spaced apart and edgewise arranged to the plane of the element and connected at alternate ends, each strip having a free end for engaging a support.

4. A resistance element comprising an integral conductor formed of a plurality of metal strips or ribbons spaced apart and edgewise arranged to the plane of the element and successively connected at alternate ends, the stripsbeing provided with ears at alternate ends for engaging supports.

5. A heating device comprising supports, and an integral resistance element formed of successive strips or ribbons spaced apart and edgewise arranged to the plane of the element'and connected at alternate ends, the stripshaving at alternate ends extensions for engaging said supports.

-6. A heating device comprising supports and integral resistance elements, formed of successive strips or ribbons spaced apart and edgewise arranged to the plane of each element, and connected at alternate ends, the strips having at alternate ends extensions for engaging said supports, a resistance elcment being mounted on either side of the 7. A heating device comprising an integral conductor formed of successive metal strips or ribbons spaced apart and edgewise arranged to the p ane of the unit and connected at alternate ends, the successive strips being provided at alternate ends with extensions, and supports for the unit comprising supporting rods, and insulating washers threaded on said rods between which said extensions are mounted.

In witness whereof, I have hereunto set my hand this 27th day of December 1916.

"EDGAR F. COLLINS; 

